Method and apparatus for removal of moisture from rotor blades

Abstract

Composite rotor blades are constructed from a honeycombed polymer interior core structure having a bonded glass skin covering associated with the top and bottom surfaces thereof. Over time, environmental conditions lead to cracks or fissures in the glass skin coverings allowing moisture to accumulate in the interior honeycomb core of the blade. The present apparatus and method removes this accumulated moisture from composite rotor blades as well as from other objects constructed of polymer composite materials in general and includes an atmospherically sealed container of sufficient size to house the rotor blades or other objects within the container. The apparatus includes support fixturing for holding the rotor blades or other objects suspended within the container, a dehumidifier to reduce the moisture level of the air cycled through the container, a heater to control the temperature within the container, and a vacuum mechanism for controlling the pressure inside the container. By exposing the rotor blades or other objects to heated dry air and controlling the interior temperature and pressure of the container, the rotor blades or other objects are efficiently and economically purged of the accumulated moisture without invasive cutting of the blade or other object surfaces. Cyclical heating and cooling of the container as well as cycling the internal pressure of the container between atmospheric pressure and a pressure below atmospheric pressure will speed up the moisture removing process and compress the overall time involved.